Computing devices, such as notebook computers, personal digital assistants, mobile communication devices, portable entertainment devices (e.g., handheld video game devices, multimedia players), and set-top-boxes (e.g., digital cable boxes, digital video disc (DVD) players) may include user interface devices that facilitate interaction between a user and the computing device.
One type of user interface device that has become more common operates by way of capacitance sensing. A capacitance sensing system may include a touchscreen, touch-sensor pad, a touch-sensor slider, or touch-sensor buttons, and may include an array of one or more capacitive sensor elements. Capacitive sensing typically involves measuring, through sensor signals, a change in capacitance associated with the capacitive sensor elements to determine a presence of a conductive object relative to the capacitive sensor elements. The face of a touchscreen capacitance sensing system, which displays images, is sometimes partially covered by an opaque material to hide capacitance sensing circuitry from the user.